1. Evaluation of terminal sire breeds for hair sheep production systems on lamb birth, weaning and grazing performance: Year 3
A.R. Weaver1, D.L. Wright1, D.R. Notter1, A.M. Zajac1, S.A. Bowdridge2, and S.P. Greiner1
1Virginia Tech, Blacksburg, VA
2West Virginia University, Morgantown, WV

2. Introduction
Purebred Katahdin

3. Terminal Sire Options Suffolk Texel Forage adaptability???
Traditional terminal sire
Fast growth
Muscle development
Moderate mature size
Forage adaptability???

4. Objective
Evaluate the efficacy of terminal sire breeds in hair sheep production systems to produce higher valued market lambs in terms of survivability, growth and parasite resistance

5. Experimental Design- Animals
Katahdin Ewes (n = 52)
n = 19
n = 19
n = 14
Katahdin Ram (n = 2)
Texel Ram (n = 2)
Suffolk Ram (n = 2)
Purebred Katahdin Lambs (n = 31 weaned, 13 male progeny)
Suffolk – Sired Lambs (n = 24 weaned,
20 male progeny)
Texel – Sired Lambs (n = 34 weaned,
17 male progeny)

6. Experimental Design Management- Forage Based System
Southwest Virginia Agriculture Research and Extension Center, Glade Spring, VA
Spring-Born Lambs
Weaned Early June (70 d)
Summer Grazing Trial (90 d)
Male progeny only
Grazing Trial Management
BW, FAMACHA, FEC and PCV every 14 d
Dewormed at FAMACHA score ≥ 3

7. Statistical Analysis SAS (SAS Institute Inc., Cary, NC)
Proc GLM: fixed effects of sire breed
Proc MIXED for repeated measures analysis
Tukey’s HSD test was used for a comparative means analysis

8. Year 1 and 2 Summary Trait Katahdin Suffolk Texel Survivability
Birth Weight
Weaning Weight
Post Grazing Weight
Harvest and Carcass WT
12th Rib Fat
LMA
Leg Score
Parasite Resistance

9. Adj. Number Born/Weaned
NLB: P = 0.83
NLW: P = 0.82

10. Adj. Birth Weights
P < 0.01

11. Adj. Weaning Weight
P = 0.55

12. Pre-weaning Summary No differences in NLB/NLW Birth weights
Texel-sired lambs heavier

13. Grazing ADG
P = 0.78

14. Adj. Post-Weaning Weight

15. Growth Summary
No differences in growth performance

16. Fecal Egg Counts

17. Packed Cell Volume

18. Average FEC and PCV over grazing period

19. Average FEC and PCV over grazing period

20. FEC and PCV Summary
Suffolk-sired lambs consistently greater FEC and lower PCV
Texel-sired intermediate to Katahdin and Suffolk-sired lambs for both traits

21. Days to Deworming FEC at Deworming PCV at Deworming P = 0.98 P = 0.06

22. At Deworming Summary
Katahdin lambs had the lowest deworming % and the greatest FEC at deworming (FAMACHA = 3)
No differences between sire breeds for days to deworming or PCV at deworming

23. Summary and Conclusions
Trait
Katahdin
Suffolk
Texel
Pre-weaning
Growth
FEC and PCV
Deworming
But…

25. Summary and Conclusions
Trait
Katahdin
Suffolk
Texel
Pre-weaning
Growth
FEC and PCV
Deworming
Carcass Merit
Total 3 1
4.5
Texel sires provide the best combination of growth and carcass composition while maintaining a level of parasite resistance in their progeny

26. Acknowledgements Zajac Parasitology Lab
Dr. Anne Zajac
Kate Pouliot
Lauren Page
Southwest Virginia Agricultural Research and Extension Center (Glade Spring, VA)
Lee Wright
Jessica McAllister
Jerry Rhea
Eric Rutherford

27. Questions